COLURES (Lat. coluri), in Astronomy and Geography, two circles, one of which passes through the equinoctial points, and is denominated the equinoctial colure; the other intersects the equator at the distance of 90° from the former, and is called the solstitial colure. The term is chiefly employed in the older treatises on astronomy.
"The space of seven continued nights he rode
With darkness, thrice the equinoctial line
He circled, four times cross'd the carr of Night
From pole to pole, traversing each colure."—Paradise Lost, B. ix.